Tritone substitution
As tritone substitution is usually referred to the replacement of a dominant seventh by a dominant seventh chord whose root a tritone is located. The term already explains the principle: A chord is replaced by another chord. The root notes of these two chords are a tritone apart. This is often used in the fifth level of a II-VI cadenza in jazz, i.e. H. the V is replaced by a bII II-bII-I , but also on all other dominants (double dominants etc.). In modern jazz, tonic and subdominant are also substituted. This chord is often referred to here as the secondary dominant.
The tritone substitution can also be viewed as a reinterpretation of the starting chord (cf. publications by Werner Pöhlert , e.g. basic harmonics ); Here the fifth case ("permanent quintal case", ie the circle of fifths as the starting point for the considerations) is expanded by placing a second next to it, which is shifted by a tritone. Chromatic is thus equated with the classic fifth case. A number of other harmony teachers take a similar point of view, e.g. B. Frank Haunschild .
The tritone substitution offers a wide range of possibilities for “shaping feelings” - that is, of emotional expression - and is therefore often used in jazz , soul , barbershop and gospel and expands the harmonic possibilities of simple cadences. Its pure form, interpreted by analysis as an excessive third-fourth chord, found its way into the Viennese classical music . Another, common classical view of the pure form is to consider the chord as a classical dominant seventh chord with a lower fifth in the bass (i.e. as V7 or D7 with b5 or> 5 in the bass).
Education as a dominant seventh chord
The tritone substitution of a dominant seventh chord is the most common variant. If one proceeds from the root G to the tritone Db and then forms a dominant seventh chord (Db7), which is played instead of the G7, one speaks of a tritone substitution. The third of the G7 chord is an b, the seventh is an f. If the root is now a tritone lower, i.e. at Db, this Db7 chord now contains f as a third and b ( confused enharmonically as ces) now as a seventh. The tension generated by the tritone between the leading and sliding notes of the dominant remains in the tritone substitution, so that alienated but plausible arcs of tension arise.
Two possibilities as a dominant seventh chord are briefly presented here:
Pure form (hidden, dark coloring)
The fifth of the starting chord (here: G7 to G7 / b5) is altered by a semitone downwards (from D to Db), so that an exchange chord (here: Db7 / b5) is built up on the tritone, which is now used as the root which corresponds exactly to the structure of the starting chord and at the same time opens up the possibility of changing to a new tonic.
Example:
| Starting chord G7 / b5 = substitution chord Db7 / b5 | ||
|---|---|---|
| chord | G7 / b5 | Qb7 / b5 |
| G / Fig | Prime | diminished fifth |
| H / Cb | major third | minor seventh |
| Db | diminished fifth | Prime |
| F. | minor seventh | major third |
The chord G7 / b5 thus contains the following tones: G, B, Db, F. Db7 / b5 contains Db, F, Abb (pronounced: Asas), Cb, which - confused enharmonically (Abb = G, Cb = B) - completely to match. So is G7 / b5 - purely regarded physically - equal Db7 / b5.
The structure has the identical structure: 1-3 and 5-7: major third, 3-5 and 7-1: major second.
This also makes it clear that the technique of the lower alternation of the fifth can only work with major chords, since the major third determines this character, while the minor seventh determines the functional meaning almost exclusively on the dominant.
Due to the relationship in the structure of the chords, it is possible to reinterpret them and thus use them as a common chord modulation between two keys:
G7 / b5 = dominant, i.e. C major or C minor = tonic, but also
Db7 / b5 = dominant, i.e. F # major or F # minor = tonic
In this way, e.g. B. A modulation from C major or C minor via Db7 / b5 to F # major or F # minor is possible.
Due to the close relationship of the structure, there are only six such chords, including enharmonic mix-ups:
| chord | C7b5 | C # 7b5 | D7b5 | D # 7b5 | E7b5 | F7b5 |
| corresponds | F # 7b5 | G7b5 | G # 7b5 | A7b5 | A # 7b5 | H7b5 |
Mixed form (open, lighter color)
In practice, the fifth of the starting chord (here: G7 to G7 / # 5) is altered by a semitone upwards (from D to D #) and at the same time the root note (here: = bass note) is shifted to the tritone, which is also here on the Tritone a swap chord (here: Db7 / 9) can be built up. Theoretically, one can still consider the shift of the fundamental to the tritone - as in the 1st case - as a downward alteration of the fifth, with an additional 5 # added. However, this does not help to understand the sound, so the practical approach is preferable. The mixed form consists of using both the 5b and the 5 #.
Here, too, the tritone substitution chord must be viewed as a dominant seventh chord due to the minor seventh, which then leads into the tonic itself (chromatic bass sequence II-IIb-I) or the tonic of the substitution (II-IIb-Vb).
Example (with reasonable voicing ):
| Starting chord G7 / # 5 = substitution chord Db7 / 9 | ||
|---|---|---|
| chord | G7 / # 5 | Qb7 / 9 |
| D # / Eb | excessive fifth | major ninth |
| H / Cb | major third | minor seventh |
| F. | minor seventh | major third |
| G -> Db | Prime | Prime |
Qb7 / 9 is again a dominant seventh chord because of the minor seventh (tonic or the subdominant use the major seventh), so that it also leads back to the tonic listed above.
The alterations of the 5th tone presented above can be colored in their tonal character by further alterations and addition tones. Mixed forms of the tritone substitution types presented above are popular and often used in jazz.
Example with further alterations
Another example of the tritone substitution of G7 / alt. through Qb7 / alt .:
| Starting chord G7 / old = substitution chord Db7 / old | ||
|---|---|---|
| chord | G7 / # 5 | Qb7 / 5b / 9/13 |
| A # / Bb | excessive none | great tredezimes |
| G / Fig | Prime | diminished fifth |
| D # / Eb | excessive fifth | major ninth |
| H / Cb | major third | minor seventh |
| F. | minor seventh | major third |
| G -> Db | Prime | Prime |
Use as a dominant seventh chord
As mentioned above, the tritone substitution is often used in a II – V – I connection: Example C major. A II – V – I connection in C major would be: Dm7, G7, Cmaj7 (= ladder- specific four-notes of a C major scale ). If you now use the tritone substitution, you get a II-bII-I compound. Using the example of C major: Qm7 - Qb7 - CMaj7. C minor: Dm7 / b5 - Db7 - Cm7. (All example chords can be changed / expanded by alterations and option tones, e.g. Dm7 / b5 / 11 omit 3 - Db7 / b5 - Cxxx) In the II-VI connection, the dominant or its substitution likes to take a half or one whole bar.
The substituted chord leads spontaneously from an easier to a heavier beat. In practice, this can be achieved by simply replacing the bass tone. The root of the replacement chord forms a walking bass- typical chromatic passage tone to the next chord (e.g. G7 – Db7 – CMaj7). It pays off if voicings are kept as few fundamental tones and fifths as possible. The more altered notes are added instead, the sooner the chord is stabilized. The above table shows the relationship of altered notes to the tritone-substituted dominant seventh chord.
Well-known examples
- Antônio Carlos Jobim : The Girl from Ipanema (Garota de Ipanema), bars 6 and 8 of the scheme
- Dizzy Gillespie : A Night in Tunisia , introduction and part A
Formation as a tonic type chord
- As a major chord: In more modern jazz, tritone substitution is used on chords of the tonic type (tonic Maj7 / subdominant Maj7 - both in major and minor ). These chords then sound very "strange".
Tonic type chords are the tonic and subdominant chords, because adding the fourth tone creates a MAJ7 chord, i.e. a major seventh chord.
In terms of effect, it is perceived as static, if not even as "rigid". It sounds very exotic or atonal.
Example: Cmaj7 / 5b = F # 7 / sus4 / 5b (CE- Gb / F # -H)
This Sus chord is played in place of the tonic or the subdominant. By changing the bass, the listener completely loses touch with the original key, so that a subsequent hard key change can no longer be perceived by the untrained ear in a harmonic context.
It is a good example of an abstract chord and one of the "lightest" chords (example of a "dark" chord: m7 / b5).
- As a minor chord: Example: C minor Maj7 / 5b = F # 6 / sus4 / 5b C - Eb - Gb / F # -H)
Formation as a sus chord
Example: Cmaj7 / sus4 / 5b = F # maj7 / sus4 / 5b (C- F- Gb / F # -H)
The third is shifted up a semitone (4-3 leading chord - without resolution), whereby the fifth - as in the classic use as a dominant seventh chord - is shifted down by a semitone (alteration of the fifth).
This chord has a symmetrical structure (quart-small second - fourth - small second). Since it does not contain a third, it is genderless like all Sus chords. It is used (because of the large 7) as a tonic or subdominant chord. Because it contains two small seconds, it is one of the most exciting chords.